Methyltransferase-like 3 promotes cervical cancer metastasis by enhancing cathepsin L mRNA stability in an N6-methyladenosine-dependent manner

N6-methyladenosine (m6A) is a highly abundant RNA modification in eukaryotic cells. Methyltransferase-like 3 (METTL3), a major protein in the m6A methyltransferase complex, plays important roles in many malignancies, but its role in cervical cancer metastasis remains uncertain. Here, we found that METTL3 was significantly upregulated in cervical cancer tissue, and its upregulation was associated with a poor prognosis in cervical cancer patients. Knockdown of METTL3 significantly reduced cervical cancer cell migration and invasion. Conversely, METTL3 overexpression markedly promoted cervical cancer cell metastasis in vitro and in vivo. Furthermore, METTL3 mediated the m6A modification of cathepsin L (CTSL) mRNA at the 5′-UTR, and the m6A reader protein insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) bound to the m6A sites and enhanced CTSL mRNA stability. Our results indicated that METTL3 enhanced CTSL mRNA stability through an m6A-IGF2BP2-dependent mechanism, thereby promoting cervical cancer cell metastasis. These findings provide insights into a novel m6A modification pattern involved in cervical cancer development.     

m6A甲基化酶METTL3在癌症发生发展中的作用

N6-甲基腺苷（m6A）是RNA中最普遍的表观遗传修饰。甲基化酶样3（methyltransferase like 3,METTL3）作为最主要的甲基化酶,参与m6A所调节的RNA的剪接、运输、翻译和降解等生物过程。目前,诸多研究证实METTL3在人类癌症中发挥着重要作用且影响癌症进展。METTL3能够通过多种机制调控癌症的发生发展:影响癌细胞甲基化水平、mRNA稳定性、调节癌细胞转化、相关信号通路、细胞凋亡等。因此,深入研究癌症发展机制,阐明METTL3调节癌症的发病机理,对癌症诊疗具有重要的理论意义和应用价值。本文通过对METTL3在多种癌症中的调节机制进行整理和分析,并总结了METTL3在各种癌症发生和发展中的最新研究进展。      

甲基转移酶样因子3 通过调控GLUT4-mTORC1 轴影响食管鳞状细胞 癌细胞的糖酵解及增殖

目的：探讨甲基转移酶样因子3（METTL3）在食管鳞状细胞癌（ESCC）组织和细胞中的表达水平及其对ESCC 细胞糖 酵解和增殖能力的影响和潜在的分子机制。方法：基于TCGA 数据库分析METTL3 在ESCC 细胞中的表达及可能的富集通路。 收集2021 年1 月至2021 年6 月间在北川医学院附属医院外科手术切除的34 例ESCC 组织及相应癌旁组织,采用免疫组化法验证 ESCC 组织中METTL3 的表达。采用CCK-8 法和平板克隆形成实验检测干扰METTL3 后ESCC 细胞增殖能力的变化,利用比色 法检测干扰METTL3 后ESCC 细胞总RNA 中m6A 的表达水平,采用甲基化RNA 免疫沉淀定量PCR（MeRIP-qPCR）检测METTL3 对葡萄糖转运蛋白4（GLUT4）基因mRNA 的m6A 修饰水平的影响,采用WB 和qPCR 等技术探索METTL3 参与ESCC 细胞糖酵解 的生物学机制。结果：METTL3 在ESCC 组织以及细胞中均呈高表达（均P<0.001）。干扰METTL3 表达后,ESCC 细胞的增殖能 力明显减弱、细胞内总RNA 的m6A 修饰水平显著降低（均P<0.001）。此外,干扰METTL3 可显著抑制KYSE150 和TE-1 细胞中 GLUT4 基因mRNA 的m6A 修饰水平（均P<0.01）,并通过下调GLUT4 的表达抑制葡萄糖的摄取以及乳酸的释放（均P<0.01）,最 终下调mTORC1 通路活性并抑制ESCC 细胞的增殖;在干扰METTL3 的ESCC 细胞同时联合运用mTORC1 通路抑制剂显示有协 同的抗癌作用。结论：METTL3 介导的m6A 修饰通过调控GLUT4-mTORC1 信号轴影响ESCC 细胞的糖酵解及增殖。     

RNA m6A methyltransferase METTL3 promotes colorectal cancer cell proliferation and invasion by regulating Snail expression

Nitrogen 6-methyladenosine (m⁶A) is the result of methylation of nitrogen-6 on adenosine, and is the most abundant chemical modification of eukaryotic mRNA. Dysregulation of m⁶A methylation has been implicated in cancer development and progression through various mechanisms. This type of methylation is primarily regulated by methyltransferase-like 3 (METTL3). However, the molecular mechanisms underlying the role of METTL3 in colorectal cancer (CRC) have not been extensively elucidated. The present study explored m⁶A modification and the underlying mechanism of m⁶A, which serve regulatory roles in the development of CRC. It was found that METTL3 is upregulated in CRC cell lines and tissues, and its expression positively correlated with poor overall survival (OS). Mechanistically, the present study demonstrated that METTL3 methylates Snail mRNA, thus stabilizing it to promote CRC malignancy. The present findings indicate that m⁶A modification is involved in CRC tumorigenesis, and highlight its potential as a therapeutic target against CRC.     

m6A甲基化修饰在肿瘤中作用的研究进展

RNA的表观遗传修饰在恶性肿瘤中发挥着重要的调控作用,因此受到人们的广泛关注。N6-甲基腺嘌呤是发生于腺苷N6位上的甲基化修饰,是真核细胞信使RNA上主要的表观遗传修饰。m6A甲基化修饰由m6A甲基转移酶催化,其核心组分包括METTL3、METTL14;由m6A去甲基化酶去除,包括FTO、ALKBH5;并被m6A甲基识别蛋白识别,包括YTHDF1-3、IGF2BP1-3等等。m6A甲基化修饰参与RNA代谢的各个阶段,包括:稳定、剪接、出核、翻译和降解等。m6A相关调节蛋白能够通过多种机制调控肿瘤的发生发展:影响m6A甲基化修饰水平,进而在肿瘤细胞增殖、侵袭转移及耐药等过程中发挥重要作用。目前为止,m6A甲基化修饰在人类肿瘤中的作用机制尚未完全阐明。本文概述了m6A修饰的基本功能,并重点介绍其在肿瘤中的作用机制,最后讨论针对肿瘤中m6A修饰的治疗策略。     

m6A甲基化修饰酶ZC3H13的功能及其在肿瘤中的研究进展

N6甲基腺苷化(N6-methyladenosine,m6A)mRNA修饰在细胞分化和肿瘤发生中具有重要作用,也是近几年表观转录组学的研究热点。ZC3H13(zinc finger CCCH domain-containing protein 13)是m6A甲基转移酶复合体中的新型调控蛋白,其介导的m6A修饰在肿瘤的发生发展中起着重要作用,因此可能成为新的肿瘤表观遗传调节剂。本文将阐述一种新的mRNA m6A甲基化修饰酶ZC3H13的结构、功能及其在肿瘤中的研究进展,旨在为基础医学及临床治疗中m6A修饰的研究提供新的研究思路和治疗靶点。     

m^(6)A-RNA甲基化在NSCLC中的生物学功能研究进展北大核心

基因调节受损是许多疾病的核心,包括发育系统疾病和癌症。N6甲基腺苷的可调节的甲基化是哺乳动物RNA修饰的重要组成部分,已被越来越多的研究证明其在各种生物学过程及癌症发病机制中发挥重要作用。这种RNA化学标记可由“writers”蛋白(甲基转移酶)产生,并可由“ereasers”蛋白(去甲基酶)逆转,这些化学修饰可以由“readers”蛋白(甲基化阅读蛋白)识别,并依此来调节下游分子机制。RNA m^(6)A修饰在重要的生物学过程中起着重要作用,有研究表明,m^(6)A在NSCLC的发生、转移及侵袭方面至关重要,m^(6)A的研究也为NSCLC治疗提供了新的思路,本文就m^(6)A在NSCLC中的病因、发展、耐药等方面进行一一论述,目的是从表观遗传学方面进一步挖掘肺癌发生发展的生物学机制,为NSCLC的靶向治疗提供研究思路。     

m6A甲基化修饰在胃癌中的研究进展

N6-甲基腺苷（N6-methyladenosine,m6A）甲基化修饰是真核细胞mRNA最常见的一种表观遗传修饰方式。m6A甲基化修饰通过调控修饰mRNA,广泛参与细胞内RNA的许多生物学行为,从而影响疾病进展与肿瘤的发生。m6A RNA修饰相关因子在胃癌（gastric cancer,GC）中的异常表达,引发 m6A甲基化修饰失调,影响GC的增殖、转移与侵袭、凋亡和耐药等生物学过程。因此,本文就m6A RNA甲基化修饰在GC发生发展中的作用以及化疗耐药予以综述。      

Decreased RNA m6A methylation enhances the process of the epithelial mesenchymal transition and vasculogenic mimicry in glioblastoma

RNA N⁶-methyladenosine (m⁶A) modification is gradually thought to be an active participant in the considerable biological processes of glioblastoma (GB), providing us with a novel insight for exploring this disease. However, the role of RNA m⁶A modification during the epithelial mesenchymal transition (EMT) or vasculogenic mimicry (VM) progression has not been investigated in GB. Here we performed a research to validate the impact exerted by AlkB homolog 5 (ALKBH5), one of “erasers” for RNA m⁶A and methyltransferase-like 3 (METTL3) which adds m⁶A modification to the RNAs on the progression of EMT and VM in GB. In this study, we demonstrate that the m⁶A levels of RNAs were reduced in GB cells and glioma tissues. Patients with high mRNA expression of ALKBH5 acquired relatively shorter median overall survival (OS) time, while patients with relatively high expression of MEETL3 prolonged their disease free survival. ALKBH5 enhanced GB cell proliferation and influenced cell cycle in vitro. Decreased RNA m⁶A methylation enhanced the progression of the EMT and VM in glioblastoma cells. ALKBH5 strengthened glioblastoma growth and enhanced the EMT and VM process of glioblastoma in vivo. Our study uncovers that RNA m⁶A methylation suppresses the process of EMT and VM in glioblastoma, providing a new perspective to seek for a potential therapeutic target for GB.     

VIP增强VEGF mRNA在非小细胞肺癌细胞中的表达

背景与目的研究发现血管内皮生长因子(VEGF)和血管活性肠肽(VIP)均对肿瘤的生长具有促进作用,但VIP通过何种方式来促进肿瘤的生长还不清楚。本研究的目的是观察VIP对非小细胞肺癌(NSCLC)细胞中VEGFmRNA表达的影响。方法应用反转录聚合酶链式反应(RTPCR)技术检测VEGFmRNA在NSCLC细胞系和小细胞肺癌(SCLC)细胞系中的表达及VIP对其表达的影响。结果在NSCLC细胞系A549、GLC82、H157、H460和SCLC细胞系H446中检测到了VEGFmRNA的表达。VIP能促进VEGFmRNA在A549和H157细胞中的表达,在VIP作用8h和16h时,VEGFmRNA的表达水平达到最高,显著高于VIP作用0h时(P<0.01)。结论VIP可能通过增强VEGFmRNA在肺癌细胞中的表达和分泌,促进肺癌新生血管的生成,参与肿瘤的生长。     

基于TCGA数据库分析m6A拷贝数变异对低级别胶质瘤的预后价值

目的:基于TCGA数据库确定m6A调节因子在低级别胶质瘤中的基因特征和预后价值。方法:从TCGA数据库中下载m6A调节因子的表达数据、拷贝数变异数据和临床信息。分析研究m6A调节因子在低级别胶质瘤组和正常对照组表达量之间的差异，m6A调节因子拷贝数变异比率，m6A调节因子的拷贝数3个水平间表达量差异和m6A调节因子的拷贝数变异水平与生存之间的关系。结果:16个m6A调节因子在肿瘤组和正常对照组表达量存在差异； 9个m6A调节因子表达量存在水平间的显著差异；生存分析显示METTL3拷贝数变异两水平（缺失与正常）之间存在差异；单因素、多因素Cox生存回归分析显示METTL3的拷贝数缺失是独立的影响生存的风险因素。结论:m6A调节因子METTL3在肿瘤组中表达量上调，METTL3拷贝数缺失预示着LGG患者生存时间缩短。这一发现为进一步了解低级别胶质瘤中m6A甲基化修饰提供了线索。     

阿霉素、顺铂提升三阴性乳腺癌细胞RNA m6A甲基化水平及其机制探讨北大核心

目的:探讨DNA损伤类化疗药物阿霉素和顺铂对三阴性乳腺癌细胞MDA-MB-231的RNA m6A甲基化水平的影响及其相关机制。方法:利用MTT法检测阿霉素和顺铂对MDA-MB-231细胞存活率的影响;通过Western blot检测γ-H2AX蛋白表达;应用Dot blot检测细胞RNA m6A甲基化水平;通过RT-qPCR和Western blot分别检测RNA m6A甲基化酶METTL3、METTL14、METTL16和RBM15以及去甲基化酶ALKBH5和FTO的mRNA和蛋白水平。结果:阿霉素和顺铂均能显著降低MDA-MB-231细胞存活率,促进细胞的DNA损伤,同时提升细胞RNA m6A甲基化水平;阿霉素和顺铂处理后细胞RNA m6A甲基化酶mRNA和蛋白表达水平无明显变化,而去甲基化酶ALKBH5的表达显著减少。结论:诱发细胞DNA损伤的化疗药物阿霉素和顺铂可提升三阴性乳腺癌细胞RNA m6A甲基化水平,其机制与m6A去甲基化酶ALKBH5的降低有关。     

miR-1290通过抑制干扰素调节因子-2调控非小细胞肺癌的增殖

  目的  探讨微小RNA-1290（miR-1290）在非小细胞肺癌（non-small cell lung cancer,NSCLC）组织中的表达及其相关调控机制。  方法  采用实时荧光定量PCR检测成都市双流区第一人民医院2014年6月至2017年6月41例NSCLC患者癌组织、癌旁组织以及NSCLC细胞株A549、H460及正常支气管上皮细胞BEAS-2B中miR-1290表达;qPCR、Western blot检测癌组织、癌旁组织IRF2 mRNA和蛋白表达;将A549和H460细胞分为miR-1290 mimic组（转染miR-1290 mimic）、miR-1290 inhibit组（转染miR-1290 inhibit）和miR- 1290 NC组（不转染）。分别于转染24、48、72、96 h后采用CCK-8法检测细胞增殖能力,平板克隆形成实验检测细胞克隆形成数,Transwell小室检测细胞侵袭数,双荧光素酶报告基因实验检测miR-1290与干扰素调节因子-2（interferon regulatory factor,IRF2）3′-UTR结合情况,qPCR检测不同miR-1290表达水平的A549和H460细胞IRF2 mRNA表达。  结果  癌组织miR-1290相对表达量明显高于癌旁组织,IRF2 mRNA和蛋白相对表达量明显低于癌旁组织,差异具有统计学意义（P < 0.05）;NSCLC组织miR-1290表达与IRF2 mRNA、蛋白表达呈显著负相关（P < 0.05）。NSCLC患者中,淋巴结转移者miR-1290表达明显高于无淋巴结转移者,Ⅲ/Ⅳ期患者miR-1290表达明显高于Ⅰ/Ⅱ期,差异具有统计学意义（P < 0.05）。转染72、96 h后,A549和H460细胞miR-1290 mimic组增殖能力明显高于miR- 1290 NC组,miR-1290 inhibit组增殖能力明显低于miR-1290 NC组,差异具有统计学意义（P < 0.05）。A549和H460细胞中miR-1290 mimic组细胞克隆数和侵袭细胞数明显高于miR-1290 NC组,miR-1290 inhibit组克隆数和侵袭细胞数明显低于miR-1290 NC组,差异具有统计学意义（P < 0.05）。双荧光素酶报告基因实验显示miR-1290能与IRF2 3′-UTR结合,明显降低荧光值（P < 0.05）。A549和H460细胞中,miR-1290 mimic组IRF2相对表达量明显低于miR-1290 NC组,miR-1290 inhibit组IRF2相对表达量明显高于miR-1290 NC组,差异具有统计学意义（P < 0.05）。  结论  miR-1290在NSCLC组织和细胞中高表达,miR-1290可能通过与IRF2结合,促进肿瘤细胞的增殖和侵袭。      

Genomic and transcriptomic alterations in m6A regulatory genes are associated with tumorigenesis and poor prognosis in head and neck squamous cell carcinoma

Genetic alterations in N6-methyladenosine (m6A) regulatory genes are observed in many cancers. Recent studies have shown that newly identified m6A regulatory gene family (IGF2BPs; IGF2BP1, IGF2BP2, and IGF2BP3) were highly expressed in various types of cancer that stabilize and promote translation of multiple oncogenes, resulting in tumor development, survival and drug resistance. However, the oncogenic roles and prognostic values of IGF2BPs in head and neck squamous cell carcinoma (HNSCC) remain largely unknown. In this study, we examined the m6A regulatory genes alteration, their mRNAs expression and the prognostic values in HNSCC. We also analyzed the interaction network and functional enrichment of m6A regulators. Our results showed that m6A regulatory genes were altered in 41% (205/504) of HNSCC patients, of which IGF2BP2 was amplified in 20% (101/504) of HNSCC patents and positively correlated with its mRNA expression. Importantly, we have validated the expression of IGF2BP2 in HNSCC and normal tissue samples. Interestingly, we also found that the IGF2BP2 was frequently co-amplified with the most common oncogenes in HNSCC patients. In addition, this study found that other m6A regulatory genes such as METTL3, METTL14, WTAP, KIAA1429, ZC3H13, RBM15, ALKBH5, FTO, YTHDF1, YTHDF2, YTHDF3, YTHDC1, IGF2BP1, and IGF2BP3 were significantly upregulated in HNSCC samples. Moreover, patients with high expression of IGF2BP1, IGF2BP2, and IGF2BP3 had poor overall survival (OS) than those with low expression. Therefore, it is evident that IGF2BP family plays a key role in the oncogenesis of HNSCC and might serve as novel prognostic biomarkers and potential therapeutic targets in HNSCC.